“The censure was a factor in my decision. I don’t take a congressional censure lightly. It’s a serious stain on Congressman Rangel’s record,” said Koppell, a Democrat, who also served briefly as state attorney general.

Koppell said the ethics woes also led to Rangel’s ouster as head of the powerful Ways and Means Committee, diminishing his clout.

The reconfigured 13th Congressional District includes parts of The Bronx Koppell represents as well as northern Manhattan.

Rangel was censured for violating 11 House rules, including soliciting donations on congressional letterhead and failing to pay taxes on his Dominican villa.

It’s the first time a prominent Democrat cited Rangel’s censure as grounds to dump him.

Meanwhile, Bronx Rep. José Serrano today will announce his endorsement of Rangel for a 22nd term.